1. Field of the Invention
The present invention relates to a route search device that supplies route information corresponding to a multi-purpose request from a user, to a server device, and to a navigation device, and also relates to a route search system in which data transfer is performed via communication between a navigation device and a server device.
2. Description of Related Art
With a prior art navigation device (that is one embodiment of a route search device), when search conditions have been specified according to which the user wishes to travel, such as for example prioritization of distance, prioritization of time required, prioritization of toll fare, prioritization of toll roads, and so on, it is arranged, using a cost that corresponds to the specified search conditions, to calculate a route from the origin point to the destination for which this cost becomes a minimum, and this route is provided to the user. And there is also a per se known type of navigation device with which it is arranged to calculate all together a plurality of routes according to various search conditions, and then the user is invited to select the route that he wishes to follow, so that the user can confirm the route along which he wishes to be guided to the destination by selecting the route that he wants to use. Generally it is the case that all of the routes from the origin point to the destination are calculated on the basis of the same search conditions.
On the other hand, navigation devices are in widespread use that receive the newest up-to-date information from an external information center via broadcast or via individual communication, and that derive a route to the destination in consideration of this newest information. For example, as basic functions of a navigation device, there may be provided a function of receiving the most up-to-date traffic information, such as congestion and travel times and so on, supplied from a traffic information center via an FM multiplex broadcast or the like, a function of calculating a route to the destination that will take the shortest time in the light of this information, and a function of guiding the user along this route to the destination. And navigation devices are also in use that, in order to be able to forecast the time point of arrival at the destination with better accuracy, acquire from an information center forecast traffic information for a route by which it is possible to arrive at the destination more quickly at the time that the vehicle is scheduled to pass along that route, and that thereby calculate an optimum route to the destination and guide the user along that route to the destination. There are also systems that are adapted to acquire an optimum route that is calculated so as to reflect the newest traffic information from the information center, and to guide the user along that route to the destination.
There is a trend to improve navigation services by inputting into the terminal many different types of information stored upon external sites (thus, this information is not limited only to traffic information), and moreover by obtaining the newest version of such information. For example, route information to the destination, the time of origin, attribute information such as the availability of intermediate rest locations, and so on may be supplied by a portal site that supports travel planning at home, and that takes into consideration the most up-to-date information that changes dynamically, such as the conditions of facilities and road tolls and the state of usage of facilities and event information and so on. Services also exist that, by travel information planned upon the portal site being transferred to a navigation device via a medium or by data communication, enable the user to employ this travel information for route display, and that enable guidance to the destination based upon this travel information.
If the route that is supplied by a navigation device of this type is different from what the user decides that he wants, then the user may intentionally ask the navigation device to re-calculate another route to the destination along which the subject vehicle is to be guided so that he can deviate from this route, and the general method employed for causing this recalculation of the route by the navigation device is to set some intermediate ground point to be passed through. With this type of prior art method the possibility arises that, on the contrary, some road section upon the route that was initially supplied along which the user desires to travel may no longer be included upon the newly re-calculated route.
Thus, in Japanese Laid-Open Patent Publication 2002-286478 for example, there has been disclosed a technique by which the user can select certain roads along which he does not want to travel from among the plurality of roads making up a route that has been derived, and by which he can also select roads along which he wishes to travel from among those roads that are displayed other than those upon the derived route. Due to this, it is arranged to perform route searching in such a manner that the roads that the user does not want to employ are avoided, and so that the roads that he does want to employ are given higher priority. Since there is no setting of any intermediate ground point, but only setting of roads that the user does not want to travel along and of roads that he wants to travel along, accordingly it is possible to enhance the probability that the route that comes to be selected does indeed match the desires of the user.